1. Field of the Invention
This invention relates to a process of manufacturing a cathode ray tube, and more particularly to a method of trimming cleaning a cathode ray tube to remove slurry of a fluorescent material and so forth from an inner wall of a skirt portion of a panel of the cathode ray tube.
2. Description of the Prior Art
Conventionally, at a step of forming a fluorescent face on an inner face of a panel in a process of manufacturing a cathode ray tube, slurry of a blue fluorescent material is first applied to an inner wall of a panel, and then the panel is trimming cleaned using, for example, water to removed such fluorescent material slurry sticking to an inner wall of a skirt portion of the panel (water processing step).
According to such coventional water processing method, a panel is rotated around its axis at a speed of, for example, 5 rpm or so, and a roller is pressed against an outer periphery of the thus rotating panel to trimming clean an inner wall of a skirt portion of the panel using a cleaning nozzle secured to a known link mechanism.
In other words, the conventional method is a water processing method relying upon tracing of an outer profile of a panel. Thus, for example, an offset between an axis of a roller and an inner wall of a skirt portion of a panel is detected, and a link mechanism is moved up or down mechanically in response to such offset so that a cleaning nozzle may be kept at a fixed distance from the inner wall of the skirt portion of the panel while cleaning liquid is supplied from a cleaning nozzle to trimming clean the inner wall of the skirt portion.
With the conventional water processing method, however, since the roller is contacted with an outer periphery of the panel to trimming clean the inner wall of the skirt portion of the panel tracing the profile of the outer periphery of the panel, if there is some irregularity in profile of the outer periphery of the panel or in rotation of the panel around its axis, then vibration will take place with the roller. Scuh vibration may be transmitted to the cleaning nozzle by way of the link mechanism to cause so-called splashing of water, which leads to incomplete formation of a fluorescent face or to incomplete accomplishment of some other manufacturing step of the panel or the like. resulting in remarkable deterioration in yield and quality of cathode ray tube products.
Further, when it is tried to apply such conventional water processing method to cleaning of a cathode ray tube having a comparatively high aspect ratio such as, for example, a high definition cathode ray tube, the link mechanism will be insufficient in stroke and will not assure a sufficient strength. Besides, the offset described above will be so great that the link mechanism cannot trace the profile of the outer periphery of the panel to accurately follow a predetermined pouring locus of the cleaning nozzle. Consequently, the conventional water processing method cannot cope well with a high definition cathode ray tube.